Current supply circuit for driving high capacitance load in an integrated circuit

(19)

(11)

EP 0 496 321 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	11.01.1995 Bulletin 1995/02

(43)	Date of publication A2:
	29.07.1992 Bulletin 1992/31

(21)	Application number: 92100835.5

(22)	Date of filing: 20.01.1992

(51)	International Patent Classification (IPC)⁵: G11C 11/24, G05F 1/56

(84)	Designated Contracting States:
	DE FR GB IT NL

(30)

Priority:

23.01.1991 US 644903

(71)	Applicant: RAMTRON INTERNATIONAL CORPORATION
	Colorado Springs Colorado 80918 (US)

(72)	Inventors:
	Mobley, Kenneth J. Colorado Springs, Colorado 80908 (US) Eaton, Sheffield S., Jr. Colorado Springs, Colorado 80916 (US)

(74)	Representative: Bosotti, Luciano et al
	c/o JACOBACCI & PERANI S.p.A. Corso Regio Parco, 27 10152 Torino 10152 Torino (IT)

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References cited: :

(54)	Current supply circuit for driving high capacitance load in an integrated circuit

(57) A constant current power supply circuit for an integrated circuit memory which is well suited for driving a high capacitance load, such as a large number of sense amplifiers. A first circuit provides a constant current source (10) and a second "current mirror" circuit provides an output current proportionate to the first circuit, but at a higher desired level of current. The constant current circuit is achieved using two cross-coupled FET transistors (16,18, 16',18') and two resistances (12,22) such that the conductivity of each transistor is inversely related to the conductivity of the other. The circuit reaches a constant current equilibrium which is largely independent of operating voltage or load, but rather depends on the relative values of the components.

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